I'm tipping the last weekend in October. He'll want to leave it as late as possible without colliding with the US election or going closely after it.
If I could vote, i'd vote Latham, he is the lesser of two evils, but the election after that i'd vote Costello. If he's not the Liberal leader in the next election, i'd probably vote green or democrat and preference Labor...
I saw an interview with one of Australia's cabinet secretaries on the Sky News International that I can recieve, the guy who pulled a Clinton and admitted to smoking mariujuana but not inhaling. Anyways, he said he thought Costello would be the next Liberal leader, but what about Alexander Downer, I'd have thought that he would be a logical choice... seems like a cool headed sort of guy.
